JP4875722B2 - Device for extracting particles from exhaled breath - Google Patents

Description

  The present invention relates to an apparatus for extracting particles from an exhaled breath, and more particularly, to an electrostatic precipitator for electrostatic collection of particles carried by the exhaled breath.

  An electrostatic precipitator (ESP) is a device designed to extract particles from a gas, such as air, and utilizes electrostatic forces generated by the electric field through which these particles pass. A high (tens of kV / cm) and non-uniform electric field is induced by the two electrodes. In the electrostatic precipitator described above, in a pocket of less than 1 millimeter of ionized gas, which generally surrounds one of the electrodes in the form of a point or wire. A discharge is generated and a high negative potential or a positive potential is reached, and a phenomenon called a corona action is reached. The gas pocket is spherical in the case of a point-like member and cylindrical in the case of a linear member. The flow of ions originating from this pocket is called an ion wind and sweeps through most of the interelectrode space. It covers the subsequently charged particles. They are highly sensitive to Coulomb forces and they are carried on a grounded cylindrical or planar counter electrode.

  The effectiveness of electrostatic precipitators is significant for all sizes of particles having a minimum size of less than about 1 micron. Devices that operate according to this principle are commercially available (eg, from United Air Specialists, Inc.). Their advantage is compactness and a yield of about 1 for particles larger than 1 micron. The main drawback of these systems is the low yield for submicron particle collection.

  In order to improve the yield of electrostatic precipitators in the collection of submicron particles, certain electrostatic precipitators contain particles that are collected in a unit located upstream of the collection unit. The air being mixed with the water vapor introduced in the form of droplets or dry steam is premixed. The first case is a water spray cleaner in which droplets collect particles. This type of electrostatic precipitator is, for example, a wheel abrater air volume control ink. (Wheellabor Air Pollution Control Inc.). The trapping of particles occurs as a result of the droplets having a velocity relative to the velocity of the gas while they move at the velocity of the gas, for example by different mechanisms such as gravity, inertia and turbulence It is possible to control. In the second case, a collection mechanism linked to nucleation is added to the collection mechanism. If the temperature of the injected water vapor in the ionic wind zone is lowered sufficiently below the vapor saturation temperature, the water vapor is condensed around particles that act like nucleation sites. The size of the droplets that are capable of transporting small particles is therefore increased by condensation, thus making the small particles more sensitive to electric fields. Although in both cases small particles can be collected with a sufficient yield, these electrostatic precipitators are intended for industrial use and in the first case they are very Large volumes of water (tens of liters per hour) may be required. They are therefore not suitable for portable use.

  More generally speaking, due to their respective sizes, the electrostatic precipitators described above are suitable for applications that allow electrostatic collection of particles carried by the discharged breath in a portable microsystem. Absent.

  An object of the present invention is to propose a device that is adapted for portable use, is capable of extracting particles from exhaled breath, and has reduced energy consumption. More particularly, it is an object of the present invention to propose an apparatus for electrostatic collection of pathogens carried by exhaled breath for subsequent analysis.

  This object has the features presented by the system for the analysis of particles extracted from exhaled breath, by the device for extracting particles from exhaled breath and in the independent claims, This is achieved by an electrostatic precipitator for electrostatic collection of particles conveyed by the carrier.

  More specifically, this object is achieved by a device for extracting particles from the exhaled breath, which has a cooling system for generating droplets by condensation of water vapor contained in the exhaled breath, a grid shape. And a droplet collection unit provided with a side wall converging towards the outlet opening, allowing droplets attracted towards the side wall to flow toward the outlet opening along the latter, and A discharge electrode attached to the inside of the droplet recovery unit, and a side wall of the droplet recovery unit defines a counter electrode for the discharge electrode, and a droplet for collecting particles carried by a discharge breath, Pull toward the side wall.

  Therefore, it is possible to produce a device that can extract particles from exhaled breath, is suitable for portable use, and has reduced energy consumption.

  According to a preferred embodiment, the side wall of the droplet collection unit has a plurality of conductive strips. The conductive strip converges towards the outlet opening and is preferably formed from metal. Preferably, the conductive strips are spaced from one another so as to obtain a grid function.

  The grid configuration allows discharge breaths to freely exit the droplet collection unit. Thus, the exhaled breath can freely exit the droplet collection unit without interfering with the process of collecting the droplet that captures the particles carried by the exhaled breath.

  According to a preferred embodiment, the droplet collection unit is formed in a conical shape having a tip and has the outlet opening. The conductive strip is followed by a conical generator defining a droplet collection unit. In other words, the conductive strip is supported downstream by the tip of the cone and upstream by the base of the cone.

  The conical shape advantageously allows the droplet collection unit to be applied for use in a portable system.

  The discharge electrode can be manufactured as a dotted member or a linear member. The inside of the side wall of the droplet collection unit is preferably rendered hydrophilic by surface treatment. This treatment can be a silicon oxide deposition. Further, a groove can be formed inside the side wall of the droplet recovery unit. The outside is preferably rendered hydrophobic by surface treatment.

  Therefore, the flow of the liquid droplets collecting the particles carried by the discharge breath along the side wall of the liquid droplet collection unit toward the latter outlet opening is improved.

  The cooling system preferably has a chamber having an inner wall, the inner wall being rendered hydrophobic by surface treatment. The droplet recovery unit is connected downstream of the cooling system.

  Thus, the flow of droplets generated by the condensation of water vapor contained in the discharge breath along the inner wall of the chamber of the cooling system towards the wall of the droplet recovery unit is improved.

  According to a preferred embodiment, the droplet collection unit comprises a fluid micro for the analysis of particles collected using droplets that flow along the sidewall of the droplet collection unit towards its outlet opening. Linked to the system. Preferably, the particles to be collected are pathogens.

  Therefore, pathogens carried by exhaled breath can be collected quickly and efficiently and analyzed by a portable system.

  The object of the present invention is also achieved by a system for analyzing particles extracted from exhaled breath, the system comprising an apparatus for collecting particles from exhaled breath and an analysis of the collected particles. And a fluid microsystem. The device for collecting particles from the exhaled breath has a cooling system for generating droplets by condensation of water vapor contained in the exhaled breath and has a grid shape and converges towards the outlet opening A droplet recovery unit provided with a side wall and allowing droplets attracted toward the side wall to flow toward the outlet opening along the latter, and a discharge electrode attached to the inside of the droplet recovery unit And the side wall of the droplet recovery unit defines a counter electrode for the discharge electrode to attract the droplet collecting the particles carried by the discharge breath toward the side wall. And the fluid microsystem for analysis of collected particles is coupled to the device for collecting particles from the exhaled breath at the outlet opening.

  The object of the present invention is also achieved by an electrostatic precipitator for electrostatic collection of particles carried by discharged breath, the electrostatic precipitator having a grid shape and at the outlet opening. A droplet collection unit provided with a converging side wall and allowing droplets attracted toward the side wall to flow toward the outlet opening along the latter, and an interior of the droplet collection unit And a discharge electrode attached to the side wall of the droplet collection unit, wherein the side wall of the droplet collection unit defines a counter electrode for the discharge electrode to attract the droplets collecting particles carried by the discharge breath toward the side wall To do.

1 is a perspective view of a system for analyzing particles extracted from exhaled breath according to the present invention. FIG. It is an expanded sectional view of the electrostatic precipitator for electrostatic collection of the particles conveyed by the discharge breath concerning the present invention. It is an expansion perspective view of the cone part of the electrostatic dust collector of FIG. FIG. 3 is an enlarged cross-sectional view of the electrostatic dust collector of FIG.

In addition to the advantages of the device and electrostatic precipitator according to the present invention, details of the embodiments will become clear from the following detailed description of the embodiments given by way of example and illustrated schematically by the accompanying drawings. ,
FIG. 1 is a perspective view of a system for analyzing particles extracted from exhaled breath according to the present invention,
FIG. 2 is an enlarged cross-sectional view of an electrostatic precipitator for electrostatic collection of particles carried by the discharge breath according to the present invention,
3 is an enlarged perspective view of a conical portion of the electrostatic precipitator of FIG. 2, and
FIG. 4 is an enlarged cross-sectional view of the electrostatic precipitator of FIG. 2, illustrating its operating principle according to the present invention.

  In the following detailed description of the accompanying drawings, identical elements are represented by identical identifications. In general, these elements and their functionality are described only once for reasons of brevity to avoid repetition. Terms such as “left”, “right”, “top”, “bottom”, “upper”, “lower”, “front” or “back” will be used in the description of the accompanying drawings. These terms usually refer to a particular position of a component in the associated diagram and can vary from diagram to diagram.

  FIG. 1 shows an example of a system 10 for analysis of particles extracted from exhaled breath according to the present invention. The exhaled breath is usually filled with water vapor and can contain particles containing pathogens, which are eg viruses, bacteria, cells, antibodies, antigens, nucleic acids etc. and analyze it It is desirable to do.

  According to a preferred embodiment, the system 10 comprises a device 30 for collecting particles from the exhaled breath and a fluid microsystem 20 for analysis of the collected particles. The device 30 has a cooling system 16 and a droplet collection unit 7 defining an electrostatic precipitator. The latter is shown as transparent in FIG. 1 for purposes of illustration.

  The cooling system 16 has a chamber 18 with an inner wall 19, which in this case is cylindrical in shape in the figure. According to a preferred embodiment, the cooling system 16 is positioned upstream of the droplet collection unit 7 and is connected to the latter by a watertight connection. The cooling system 16 can cool the water vapor contained in the discharge breath to obtain droplets by condensation of the water vapor. In the figure, the exhaled breath is conveyed toward the chamber 18 via the end portion 3.

  Nevertheless, it should be noted that as long as the particular location and embodiment of the cooling system 16 allows the latter to cool the water vapor contained in the exhaled breath to obtain droplets by condensation, It is not limited to those shown in 1. For example, the cooling system 16 and the droplet recovery unit 7 can be combined so that the water vapor contained in the discharge breath is cooled only after reaching the droplet recovery unit 7. Alternatively, the droplet collection unit 7 itself can be cooled, for example by contact and conduction with the cooling system 16. Thus, different embodiments can be envisioned and widely considered.

  As shown in FIG. 1, the droplet collection unit 7 has a side wall 2, which preferably defines a shape that converges toward an outlet opening 9 provided at the lower tip 8. To do. The side wall 2 has an inner side 4 and an outer side 5. As will be described later with reference to FIGS. 2 to 4, the droplet collection unit 7 is advantageously grid-shaped.

  The discharge electrode 1 is attached inside the droplet recovery unit 7, and the discharge electrode 1 can generate an ion flow from a pocket of ionized gas surrounding the discharge electrode 1. In order to allow the generation of the above ion flow, the side wall 2 defines a counter electrode for the discharge electrode 1. In this way, the droplets that can collect the particles conveyed by the discharge breath are carried away by the flow of ions from the position of the discharge electrode 1 toward the side wall 2 of the droplet recovery unit 7. Along these trajectories, these droplets capture the particles to be collected and transport them towards the side wall 2 or the droplets with the captured particles are exited along the side wall 2 The liquid film 6 flowing to the micro system 20 is formed through the latter toward the part 9.

  According to a preferred embodiment, an outlet opening 9 is attached to each inlet of the microsystem 20. The latter is connected to the device 30 by, for example, adhesion to recover the collected particles.

  The microsystem 20 includes a silicon substrate 21 having fluid chambers and passages such as chambers 22 and 23 and passages 24. The latter can be formed on the upper surface of the substrate 21 by photolithography and standard silicon etching techniques. Depending on the requirements or procedure for analysis of each sample collected via the device 30, the fluid chambers 22, 23 and the passage 24 can be provided with a depth on the order of 10-500 μm.

  The fluid components of the microsystem 20 are watertight by attaching a silica wafer 40 formed with holes that function as inlet-outlets for the microsystem 20 to the top of the substrate 21. Alternatively, the silica wafer 40 can be formed from glass, plastic or other materials that can make the microsystem 20 watertight. The assembly of the wafer 40 and the substrate 21 can be performed irreversibly by coating the adhesive on the substrate 21 around the fluid parts of the components, ie around the chambers 22, 23 and the passages 24. The coating of the adhesive material is formed by screen printing of an adhesive material, for example. A suitable process is described in French Patent No. 2856047.

  Thus, multiple microsystems 20 can be assembled on a single wafer as described above. Once assembly is thus achieved, the wafer can be cut into individual components by cutting using an appropriate cutter.

  Nevertheless, it should be noted that one skilled in the art knows the production of fluid microsystems suitable for the analysis of particles collected from exhaled breath. Accordingly, a more detailed description of the micro system 20 and its operation is omitted for the sake of brevity.

  FIG. 2 shows an enlarged cross-sectional view of the device 30 for collecting particles from the exhaled breath of FIG. As shown in FIG. 2, the chamber 18 of the cooling system 16 is hermetically sealed against the distal end 3 by a seal 17, and the discharge electrode 1 is a point-like member 15.

  Alternatively, the discharge electrode 1 can be formed as a linear member, in particular as a polarized linear member. This is because the above-mentioned linear member is capable of generating a wider discharge zone than the point-like member 15 and is located so that the corresponding discharge zone surrounds the entire length of the linear member. Allow collection of particles from. As an example, a suitable discharge zone can be generated by applying a discharge voltage of 10 KV to a linear member having a diameter of 50 μm. This voltage can be increased for linear members having larger diameters. It can be reduced for linear members having a smaller diameter, for example linear members having a diameter of 10 microns.

  According to the embodiment, the linear member is formed of a conductive material having mechanical resistance, such as tungsten. Preferably, the material used can be welded or soldered, such as copper. The linear member is preferably positioned parallel to the axis of the droplet recovery unit 7, preferably parallel to the central axis thereof, and fixed to a predetermined position by the support means. Is supported, for example, on the inner side 4 of the side wall 2 and connects the end of the linear member to the latter, but does not interfere with the flow of collected droplets. According to an embodiment, the three coplanar supports spaced approximately 60 degrees apart from one another thus constitute a star-shaped support and function as support means at each end of the linear member To do.

  As described above, according to a preferred embodiment, the droplet collection unit 7 of the device 30 is grid-shaped. The side wall 2 has, for example, a plurality of conductive strips 34 converging towards the outlet opening 9. The latter are preferably interconnected by struts 37 and spaced by gaps 35. The conductive strip 34 defines a counter electrode for the discharge electrode 1 and is preferably made of metal.

  The gaps 35 are displayed in an oversize in order to clearly explain their layout. Nevertheless, the droplets transported all the way towards the side wall 2 can freely flow along the side wall 2 towards the outlet opening 9 and the exhaled breath, ie any noncondensable gas, The gap 35 should be laid out so that it can move freely from the droplet collection unit 7.

  FIG. 3 shows the droplet recovery unit 7 of FIG. 1 in an enlarged perspective view. The latter clearly shows the grid shape of the collection unit 7 with the conductive strip 34, the gap 35 and the column 37. Only a portion of the conductive strip 34 and the gap 35 are shown using an identification display for clarity of display.

  As shown in FIG. 3, the droplet collection unit 7 is preferably formed in a conical shape having a base 32 and a tip 8 having an outlet opening 9. The conical shape of the recovery unit 7 is defined by a conical generator that supports the conductive strip 34. In the embodiment shown in FIG. 3, the conductive strip 34 represents a conical generator, downstream by the conical tip 8 and upstream by its base 32, ie the cooling system of FIG. 16 is held by the downstream portion.

  Said embodiment of the droplet recovery unit 7 and in particular its conical shape constitutes a surface which is not arranged parallel to the inner side 4 to the discharge breath and thus to the trajectory of the particles carried by the latter Provides the benefits of Similar to the grid shape of the droplet collection unit 7, this surface facilitates the passage of particles close to the at least one conductive strip 34 and thus increases the effectiveness of collection of the droplet collection unit 7. Which is different from that of the structure arranged parallel to the trajectory of the particles carried by the exhaled breath.

  Nevertheless, it should be noted that other embodiments are possible. For example, assuming that the functionality described in the context of the present invention is ensured, the conductive strip 34 can be formed into a ring shape, a spiral shape, a chevron shape, or other shapes. It is. All these different embodiments are therefore considered.

  It should be noted that the droplet collection unit 7 shown in FIG. 3 has a plurality of support columns 37 as an example. Nevertheless, according to a preferred embodiment, the conductive strip 34 has a first strut provided close to the base 32 of the droplet collection unit 7 and a second strut provided close to the tip 8. Preferably starting from the lower end of the latter. In other words, the number and location of struts 37 that essentially function to maintain the conical structure selected to form the collection unit 7 without changing the functionality of the droplet collection unit 7. It is possible to correct.

  Several techniques can be envisioned and considered to form the conical shaped droplet collection unit 7 of FIG. For example, it is possible to use an appropriately sized cone made of stamped aluminum alloy. In this conical portion, as with the outlet opening 9 at the tip 8 of the conical portion, the side discharge slot defining the gap 35 is formed by laser cutting.

  FIG. 4 shows the operating principle of the device 30 of FIG. 1 according to the invention. According to a preferred embodiment, the exhaled breath 60 is conveyed towards the cooling system 16 via the end 3. The exhaled breath 60 is filled with water vapor and contains particles 66 to be collected.

  In the cooling system 16, the exhaled breath 60 is cooled to obtain water vapor droplets by condensation. These droplets are conveyed toward the side wall 2 of the droplet recovery unit 7 by the flow of ions generated from the pockets of the ionized gas 50 surrounding the point-like member 15 of the discharge electrode 1. In their trajectories, the resulting droplets capture the particles 66 and transport them towards the side walls 2, as indicated by arrows 70 for illustration.

  Upon arrival at the side wall 2, the droplets form a liquid film 6 there and flow along the side wall 2 toward the outlet opening 9. Since the operation of the electrostatic precipitator, for example as defined by the device 30, is generally known to those skilled in the art, a more detailed description is omitted here.

In order to improve the operation of the device 30, the inner side 4 of the side wall 2 of the droplet recovery unit 7 can be made hydrophilic by surface treatment, for example by silicon oxide (SiO ₂ ) coating. The inner side 4 can also be structured by forming grooves directed in the direction of droplet flow, which helps to guide the flow. Further, the outer side 5 can be made hydrophobic by surface treatment. With respect to the cooling system 16, the inner wall 19 of the chamber 18 can also be made hydrophobic by surface treatment.

  Although specific embodiments have been described above, numerous variations can be made to the fastening means according to the invention without changing their functionality. Therefore, all these variations are also envisioned and generally considered.

Claims (22)

An apparatus for extracting particles from exhaled breath,
A cooling system (16) for generating droplets by condensation of water vapor contained in the exhaled breath;
A side wall (2) having a grid shape and converging towards the outlet opening (9) is provided, and droplets attracted towards the side wall (2) are directed along the latter to the outlet opening ( 9) a droplet collection unit (7) that allows it to flow towards
A discharge electrode (1) attached to the inside of the droplet recovery unit (7);
The side wall (2) of the droplet recovery unit (7) defines a counter electrode with respect to the discharge electrode (1), and the droplet collecting particles carried by the discharge breath is directed toward the side wall (2). A device characterized by attracting.   The apparatus according to claim 1, characterized in that the side wall (2) of the droplet collection unit (7) comprises a plurality of conductive strips (34).   The device according to claim 2, characterized in that the conductive strip (34) converges towards the outlet opening (9).   4. A device according to claim 2 or 3, characterized in that the conductive strip (34) is made of metal.   The conductive strips (34) are spaced apart from each other and allow the exhaled breath to freely exit the droplet collection unit (7). The apparatus of any one of these.   The said droplet collection | recovery unit (7) is formed in the cone shape which has a point part (8), and has the said exit opening part (9), Any one of Claims 1-5 characterized by the above-mentioned. The device described.   7. A device according to any one of claims 2 to 6, characterized in that the conductive strip (34) is held by a conical generator defining the droplet collection unit (7).   The device according to claim 1, wherein the discharge electrode is a point-like member or a linear member.   9. Device according to any one of the preceding claims, characterized in that the inside (4) of the side wall (2) of the droplet recovery unit (7) is rendered hydrophilic by surface treatment.   The apparatus of claim 9, wherein the treatment is a silicon oxide coating.   Device according to any one of the preceding claims, characterized in that a groove is formed on the inside (4) of the side wall (2) of the droplet recovery unit (7).   12. The device according to claim 1, wherein the outside (5) of the side wall (2) of the droplet collection unit (7) is rendered hydrophobic by surface treatment.   The cooling system (16) comprises a chamber (18) having an inner wall (19), the inner wall (19) being rendered hydrophobic by a surface treatment. The apparatus according to claim 1.   14. Apparatus according to any one of the preceding claims, characterized in that the droplet recovery unit (7) is connected downstream of the cooling system (16).   The droplet recovery unit (7) is for analyzing particles collected by droplets flowing along the side wall (2) of the droplet recovery unit (7) towards its outlet opening (9). 15. A device according to any one of the preceding claims, connected to a fluidic microsystem.   16. Device according to any one of the preceding claims, characterized in that the particles (66) are pathogens. A system for analyzing particles extracted from an exhaled breath, comprising a device (30) for collecting particles from the exhaled breath;
A cooling system (16) for generating droplets by condensation of water vapor contained in the exhaled breath;
A side wall (2) having a grid shape and converging towards the outlet opening (9) is provided, and droplets attracted towards the side wall (2) are directed along the latter to the outlet opening ( 9) a droplet recovery unit (7) that allows it to flow towards
A discharge electrode (1) mounted inside the droplet recovery unit (7);
The side wall of the droplet recovery unit (7) defining a counter electrode for the discharge electrode (1) in order to attract the droplets collecting particles carried by the exhaled breath toward the side wall (2) ( 2) and
A fluid microsystem (20) for analysis of the collected particles;
The microsystem (20) is connected to the device (30) to collect particles from exhaled breath at the outlet opening (9).   18. System according to claim 17, characterized in that the device (30) for collecting particles from exhaled breath is realized according to any one of claims 2-14. An electrostatic precipitator for electrostatic collection of particles carried by a discharge breath,
A side wall (2) having a grid shape and converging towards the outlet opening (9) is provided, and droplets attracted towards the side wall (2) are directed along the latter to the outlet opening ( 9) a droplet collection unit (7) that allows it to flow towards
A discharge electrode (1) attached to the inside of the droplet recovery unit (7);
The side wall (2) of the droplet recovery unit (7) defines a counter electrode with respect to the discharge electrode (1), and the droplet collecting particles carried by the discharge breath is directed toward the side wall (2). Electrostatic precipitator characterized by attracting.   20. The electrostatic precipitator according to claim 19, wherein the droplet recovery unit (7) is formed in a conical shape having a pointed end (8) and has the outlet opening (9). . The side wall (2) of the droplet collection unit (7) has a plurality of conductive strips (34),
21. The electrostatic precipitator according to claim 20, wherein the conductive strip (34) is held by a conical generator defining the droplet collection unit (7).   The electrostatic discharge according to any one of claims 19 to 21, wherein the droplet recovery unit (7) is cooled to produce droplets by condensation of water vapor contained in the discharge breath. Dust collector.

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